JPS62262206A - Reproducing device for magnetic recording medium - Google Patents

Abstract

PURPOSE:To instantaneously absorb azimuthal deviation by constituting a reproducing head for 1 track of plural magnetic heads and after conforming the phase of reproduction signals outputted from each magnetic head adding them. CONSTITUTION:A phase difference detecting circuit 6 finds phase difference of reproduction signals from a magnetic head 1-1 and reproduction signals from other magnetic heads 1-2-1-6, and finds delay time t1-t5 of variable delay circuits 8-1-8-5 necessary to make phase difference between output signals of a delay circuit 7 and output signals of variable delay circuits 8-1-8-5, and adds corresponding numerical values to variable delay circuits 8-1-8-5. The delay circuit 7 delays reproduction signals from the magnetic head 1-1 by a specified time T and outputs, and variable delay circuits 8-1-8-5 delay reproduction signals from magnetic heads 1-2-1-6 applied through regenerative amplifiers 5-2-5-6 by t1-t5 respectively and output them. Accordingly, phase of output signals of the delay circuit 7 and variable delay circuits 8-1-8-5 becomes conformable, and these output signals are added by an adder C and supplied to a speaker. Thus, azimuth can be reduced without changing inclination of the reproducing head.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to a magnetic recording medium reproducing device for reproducing information recorded on a magnetic recording medium such as a magnetic tape or a magnetic disk. The present invention relates to a reproducing apparatus for a magnetic recording medium that can reduce azimuth loss.

[Conventional technology]

In a magnetic recording medium playback device, such as a tape recorder, if the azimuth angle of the magnetic head used during recording differs from the azimuth angle of the magnetic head used during playback, there is a problem that the high frequency range will be attenuated during playback. .

In order to solve this problem, the 11979 minute playback head was set to the first. The second magnetic head consists of two magnetic heads, the first
．． It has been proposed to use a motor to adjust the inclination of the reproducing head so that the phase difference between the reproduced signals output from the second magnetic head becomes zero. That is, if the azimuth angles match, the first. Since the phase difference between the reproduced signals output from the second magnetic head is zero, the azimuth loss can be reduced by doing as described above.

[Problem that the invention seeks to solve]

However, in the conventional example described above, the azimuth adjustment is performed by adjusting the inclination of the reproducing head using a motor, and therefore the response speed is slow.

■Easily generates mechanical noise; ■Lack of durability and reliability. ■Changes in the inclination of the playback head tend to cause disturbances in tape running. ■In multi-track systems with two or more trunks, it is extremely difficult to perfectly match the azimuth angles of each trunk. There was a problem.

The present invention solves the above-mentioned problems, and its purpose is to reduce azimuth loss without changing the inclination of the reproducing head.

[Means for solving problems]

In order to solve the above-mentioned problems, the present invention provides a magnetic recording medium reproducing apparatus for reproducing information recorded on a magnetic recording medium, which is comprised of a plurality of magnetic heads, and includes one of the magnetic recording media.
a playback head that plays back information for a track; and a phase difference that detects a phase difference between a playback signal output from a specific magnetic head of the plurality of magnetic heads and a playback signal output from another magnetic head. a detection means; a delay means for delaying the reproduced signal outputted from the specific magnetic head for a predetermined time; and a delay means provided corresponding to the other magnetic head to delay the reproduction signal output from the other magnetic head by a time corresponding to the detection result of the phase difference detection means. The apparatus is provided with variable delay means for respectively delaying reproduction signals output from the magnetic head, and addition means for adding the output signal of the delay means and the output signal of the variable delay means.

[For production]

Azimuth loss A is expressed by the following equation (1).

A =2010g+o (x Wtan θ/λ10si
n (πWtan θ/λ)] ・−・・−・・・・・・−・+11 However, in formula (11, λ is the recording wavelength, θ is the azimuth deviation angle, and W is the track width.0 Formula +11 As can be seen, when the recording wavelength λ and the azimuth shift angle θ are constant,
The narrower the track width W, the smaller the azimuth loss A.
In other words, by using a narrow magnetic head, azimuth loss can be reduced. Therefore, by configuring a reproducing head for one track using a plurality of narrow magnetic heads as in the present invention, the azimuth loss can be reduced. Further, the reproduction signal output from the specific magnetic head is delayed by a predetermined time by a delay means, and the reproduction signal output from the other magnetic head is delayed by a time corresponding to the detection result of the phase difference detection means by the variable delay means. By delaying, the phase of the reproduction signal output from each magnetic head constituting the reproduction head can be changed.

〔Example〕

FIG. 1 is a block diagram of an embodiment of the present invention, in which 1 is a playback head, 2 is a recording head, 3 is an erase head, 4 is a magnetic tape, 5-1 to 5-6 are playback amplifiers, and 7 is a delay circuit. , 8
-1 to 8-5 are variable delay circuits, and 9 is an adder. still,
The reproducing head 1 is composed of six magnetic heads 1-1 to 1-6 arranged in a straight line as shown in FIG. Further, in FIG. 2, 1-1° to 1-6′ indicate a magnetic gap of 7 degrees 1-1-1-6.

The reproduction signal output from each of the magnetic heads 1-1 to 1-6 for reproduction is applied to the reproduction amplifiers 5-1 to 5-6, respectively, and the output signal of each reproduction amplifier 5-1 to 5-6 is are applied to the delay circuit 7 and the variable delay circuits 8-1 to 8-5, respectively, and also to the phase difference detection circuit 6. The phase difference detection circuit 6 detects the reproduced signal from the magnetic head 1-1 and the other magnetic heads. The phase difference between the output signal of the delay circuit 7 and the output signal of the variable delay circuits 8-1 to 8-5 is determined based on the phase difference between the reproduced signals from 1-2 to 1-6, and the phase difference between the output signal of the delay circuit 7 and the output signal of the variable delay circuits 8-1 to 8-5. Variable delay circuits 8-1 to 8-5 necessary to make it zero
Delay times L1 to t5 are determined, and numerical values corresponding to the delay times tl-t5 are added to variable delay circuits 8-1 to 8-5, respectively.

The delay circuit 7 delays the reproduction signal from the magnetic head 1-1 applied via the reproduction amplifier 5-1 by a predetermined time T and outputs it. 2-5-6- Magnetic head applied via 1-
The reproduced signals from 2 to 1-6 are delayed by tl to t5, respectively, and output. As a result, the phases of the output signals of the delay circuit 7 and the variable delay circuits 8-1 to 8-5 match. Then, the delay circuit 7 and the variable delay circuits 8-1 to 8-8
-5 output signals are added by an adder 9 and then supplied to a speaker (not shown) via an amplifier or the like.

FIG. 3 is a block diagram showing an example of the phase difference detection circuit 6 shown in FIG.
-1 to 5-6 are input terminals to which output signals are applied, 67 is an envelope detection circuit, 68 is a comparator, 69 is an input signal level detection circuit, 70 is a band pass filter, 71 is a comparator, 72 to 76 are input terminals. Phase difference detection section, 77 is a band pass filter, 7th is a comparator, 79 is a phase comparator, 80 is an integrator, 81 is a sample hold circuit, 82 is an A/D converter, 83 is a ROM, 84 is a launch circuit, 85 to 89 are output terminals. Note that the phase difference detection sections 73 to 76 also have the same configuration as the phase difference detection section 72. Further, FIG. 4 is an explanatory diagram of the operation of FIG. 3, and the operation of FIG. 3 will be explained below with reference to FIG.

Reproduction signals from the magnetic heads 1-1 to 1-6 are applied to input terminals 61 to 66 via reproduction amplifiers 5-1 to 5-6. Now, for example, the input terminals 61 and 62 in FIG. 4(A).

If the reproduced signals a and b shown in (B) are added, the output signals c and d of the bandpass filters To and 77 will be as shown in the same figure (C) and CD), respectively, and in addition to the comparators 71 and 78, It will be done. Comparators 71 and 78 output signals c and 78 of bandpass filters 70 and 77, respectively.
d and a predetermined darkness value, and while the signals c and d are larger, the output signals e and f are set to "1",
In this case, the output signals e and f of the comparators 71 and 78 are as shown in (E) and (F) of the same figure, respectively.

The phase comparator 79 compares the phases of the signals e and f, and if the phase of the signal e is ahead, the phase comparator 79 compares the phases of the signals e and f. A positive voltage of a predetermined level is generated from the time when the signal r rises until the signal f falls, and if the phase of the signal r is ahead, the signal f A negative voltage of a predetermined level is generated from when the signal e falls to when the signal e falls, and in this case, the output signal g of the phase comparator 79 is as shown in FIG. The integrator 80 integrates the output signal g of the phase comparator 79 and outputs the signal shown in FIG. A signal i shown in the figure (+) is output. That is, the level of the output signal i of the sample and hold circuit 81 is proportional to the phase difference between the reproduction signal output from the magnetic head 1-1 and the reproduction signal output from the magnetic head 1-2: A/D Conversion r; a2 converts the output signal i of the sample hold circuit 81 into a digital signal, and the ROM 83 converts it into an A/D signal.
Data indicating the delay time stored at the address corresponding to the digital signal output from the converter 82 is applied to the launch circuit 84. Here, each address of the ROM 83 has a delay time required to make the phase of the output signal of the variable delay circuit 8-1 match the phase of the output signal of the delay circuit 7.
The output signal of the converter 82 is stored as an address.

Further, an input signal level detection circuit 69 consisting of an envelope detection circuit 67 and a comparator 68 sets the output signal j to "1" when the level of the signal a is higher than a predetermined level, and causes the launch circuit 84 to read out the signal from the ROM 83. Latch the data indicating the delay time. The data indicating the delay time latched by the launch circuit 84 is then applied to the variable delay circuit 8-1 via the output terminal 85.

The phase of the signal a applied to the input terminal 61 is the input terminal 62
If the signal is ahead of the phase of the signal applied to the comparator 71, 78, phase comparator 79,
Output signal 41 of integrator 80 and sample hold circuit 81
4 i is as shown in Fig. 4 (E) to (1), but if the phase of the signal is ahead, the comparator 71.7B
, phase comparator 79, integrator 80, sample hold 81
The output signals e 4 + are shown in (J) to (N) in the same figure, respectively.
It will be as shown below. In this case as well, as can be seen from the figure (N), the level of the output signal of the sample hole 1 circuit 81 corresponds to the phase difference between the signals a and b.
Data indicating the delay time required to make the phase of the output signal of the variable delay circuit 8-1 match the phase of the output signal of the delay circuit 7 is read from the ROM 83.

Further, the phase difference detection units 73 to 76 operate similarly to the phase difference detection unit 72, and are configured to match the phase of the output signal of each variable delay circuit 8.2 to 8-5 with the phase of the output signal of the delay circuit 7. Each variable delay circuit 8-2 to 8-5
It is added to.

In the above-mentioned embodiment, the reproducing head l for 1" drive was constituted by six magnetic heads 1-1 to 1-6, but the number of magnetic heads is not limited to this.
Any number may be used as long as it is multiple.

Furthermore, although the above-mentioned conventional example has been explained by taking a fixed head type tape recorder as an example, it goes without saying that the present invention can also be applied to a rotary head type tape recorder or a magnetic desk device. Furthermore, although not explained in the above embodiment, by adjusting the delay times of the variable delay circuits 8-1 to 8-5, it is also possible to apply electrical echo, waveform equalization, etc. It is. Furthermore, in multi-track tape recorders with two or more trunks,
If the playback head corresponding to each track is composed of a plurality of magnetic heads as shown in Figure 2, and if the phases of the playback signals output from each magnetic head are matched, the attenuation of the high frequency range due to azimuth deviation can be avoided. It can be eliminated.

〔Effect of the invention〕

As described above, according to the present invention, the reproduction head for one trunk is constructed of a plurality of magnetic heads, and the reproduction signals outputted from each magnetic head are added together after the phases of the reproduction signals are changed once. Since there is no need to mechanically move the magnetic head as in the conventional case, it has the advantage of being able to instantly absorb azimuth deviations, as well as being highly reliable and durable. There is.

[Brief explanation of drawings]

FIG. 1 is a block diagram of an embodiment of the present invention, FIG. 2 is a plan view showing an example of the configuration of the reproducing head 1, FIG. 3 is a block diagram showing an example of the configuration of the phase difference detection circuit 6, and FIG. FIG. 3 is an explanatory diagram of the operation of FIG. 3; In the figure, l...reproduction head, 1-1 to l-6 are magnetic heads, 1-1" to 1-6°...gap, 2...
- Recording head, 3... Erasing head, 4... Magnetic tape, 5-1 to 5-6... Playback amplifier, 6... Phase difference detection circuit, 7... Delay circuit, 8-1 ~8-5...Variable delay circuit, 9...Adder, 61-66...Input terminal, 67...Envelope detection circuit, 68, 71.7
8... Comparator, 72-76... Phase difference detection section, 70
゜77... Band pass filter, 79... Phase comparator, 80... Integrator, 81... Sample hold circuit, 82... A/D converter, 83... ROM, 84
...Launch circuit, 85-89...Output terminal. Actual IN Nozulock diagram of the present invention Fig. 1 Configuration IF of the amphibious head 1 which is further used in the present invention! Plan view showing I Figure 2 Figure 3 1 masterpiece explanatory diagram theory Figure 4

Claims (1)

[Claims] A magnetic recording medium reproducing device for reproducing information recorded on a magnetic recording medium, comprising a plurality of magnetic heads, one of the magnetic recording media
a playback head that plays back information for a track; and a phase difference that detects a phase difference between a playback signal output from a specific magnetic head of the plurality of magnetic heads and a playback signal output from another magnetic head. a detection means; a delay means for delaying the reproduced signal outputted from the specific magnetic head for a predetermined time; and a delay means provided corresponding to the other magnetic head to delay the reproduction signal output from the other magnetic head by a time corresponding to the detection result of the phase difference detection means. A magnetic recording medium comprising variable delay means for respectively delaying reproduction signals output from a magnetic head, and addition means for adding an output signal of the delay means and an output signal of the variable delay means. playback device.